• 대한치과의사협회지
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• 제17권7호통권122호
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• pp.525-528
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• 1979

958 healthy Korean children aged from 2 to 11 years old (male: 500 female:458) were studied on the root resorption of the mandibular first deciduous molar. The Results were as follows: 1. The resorption of mandibular first deciduous molar in female was earlier than male. 2. The patterns of the initial resorption of mandibular first deciduous molar were as follows Distal root is resorbed by the Successor ; 55.92% Both roots are resorbed by the Successor simultaneously ; 30.51% Mesial root is resorbed by successor ; 6.33% Mesial root is resorbed by the mandibular first bicuspid and canine ; 4.08% Bifurcation area is resorbed by the successor; 3.16% 3. The Exfoliation period of mandibular first deciduous molar was 10 years 1month in female and 10 years 4 months in male.

• Journal of Chest Surgery
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• 제44권4호
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• pp.292-293
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• 2011

Surgical repair of the tetralogy of Fallot is one of the most successful operations in the treatment of congenital heart diseases. We report the case of a 65-year-old man who had an aortic valve replacement at the time of complete repair of the tetralogy of Fallot at the age of forty-three. He subsequently had progressive aortic root and ascending aorta dilation to 9 cm. The aortic root and ascending aorta replacement was done using a composite valve-graft and was performed along with other procedures. Thus, meticulous follow-up of aortic root and ascending aorta after corrective surgery for tetralogy of Fallot is recommended following initial curative surgery.

• Structural Engineering and Mechanics
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• 제2권2호
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• pp.141-156
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• 1994

In this paper, the effect of material elasticity was evaluated through a simple model as proposed by Wang and Yu (1991), for yield mechanisms of a cantilever beam under tip pulse loading. The beam was assumed rigid-perfectly plastic but instead of the usual fully clamped constraints at its root, an elastic-perfectly plastic rotational spring was introduced there so the system had a certain capacity to absorb elastic energy. Compared with a rigid-perfectly plastic beam without a spring root, the present beam-spring model showed differences in the initial plastic hinge position and the minimum magnitude of the dynamic force needed to produce a plastic failure. It was also shown that various failure responses may happen while the hinge travels along the beam segment towards the root, rather than a unique response mode as in a rigid perfectly plastic analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.78-80
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• 1994

Conventional methods for root finding of the algebraic equations are intrinsically synthetic division methods, i.e., which are the factorization in forms of $f(x)=(x-x_i)Q(x)$. So existing methods have some demerits such as deflation and root-polishing procedures. To overcome these defects a new powerful algorithm, namely circular arithmetic algorithm(CSM), was introduced and has been investigated about its fascinating properties. In this paper, we will propose a simple and effective method of getting the initial guesses for the roots of the equation. With this method the CSM can me all the root of equation with great efficiency.

• International Journal of Computer Science & Network Security
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• 제23권6호
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• pp.84-90
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• 2023

In this article the problem of computing floating-point reciprocal cube root functions is considered. Our new algorithms for this task decrease the number of arithmetic operations used for computing $1/{\sqrt[3]{x}}$. A new approach for selection of magic constants is presented in order to minimize the computation time for reciprocal cube roots of arguments with movable decimal point. The underlying theory enables partitioning of the base argument range x∈[1,8) into 3 segments, what in turn increases accuracy of initial function approximation and decreases the number of iterations to one. Three best algorithms were implemented and carefully tested on 32-bit microcontroller with ARM core. Their custom C implementations were favourable compared with the algorithm based on cbrtf(x) function taken from C ＜math.h＞ library on three different hardware platforms. As a result, the new fast approximation algorithm for the function $1/{\sqrt[3]{x}}$ was determined that outperforms all other algorithms in terms of computation time and cycle count.

• Journal of Welding and Joining
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• 제32권1호
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• pp.79-86
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• 2014

The purpose of this study is to determine the proper fillet weld size for the stiffeners on hull bottom plate of crude oil tanker. To achieve it, the effective notch stress and hot spot stress of the fillet weld with leg length specified in the rule were evaluated by using comprehensive FE analyses. Based on the results, the fatigue damages at each location of weld were calculated. Meanwhile the transitional behavior of initial welding distortion in the hull bottom plate under the design conditions was investigated by using a non-linear FEA. Welding distortion and residual stress introduced during fabrication process were considered as initial imperfections. According to FE analysis results, if the fillet leg length satisfies the design criteria of the classification society, the concern on the root failure at the fillet welds in the bottom hull plate during the design life can be negligible. In addition, considering the transitional behavior of the distortion during the service life, the fillet leg length should be minimized.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2019년도 추계학술대회
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• pp.164-164
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• 2019

• 한국자원식물학회지
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• 제26권4호
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• pp.503-510
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• 2013

본 연구는 졸참나무의 건전한 1-1 조림용 묘목을 생산하기 위해 초기 묘고가 다른 묘목에서 적절한 단근의 강도를 구명하기 위해 실시하였다. 이를 위해 1-0 노지묘의 크기를 구분하여 단근(5, 10, 15 cm)을 실시하였다. 1년의 생육기간이 지난 시점에서 묘고를 비롯한 지상부 생장량과 주근 및 측근의 발달 특성을 비교 분석하였다. 지상부의 생장은 초기 묘목 크기와 단근에 의해 다양한 차이가 나타났으며, 측근의 발달은 묘목 크기에 따른 영향이 큰 것으로 나타났다. 초기 묘고가 큰 묘목군에서는 15 cm로 단근된 묘목이 가장 우수한 지상부 생장량을 나타내었으며, 초기 묘고가 작은 묘목군에서는 15 cm와 10 cm로 단근된 묘목이 우수한 생장량을 나타내었다. 묘목 크기에 따른 생장은 초기 묘고가 큰 묘목이 작은 묘목보다 우수한 지상부 생장을 나타내었으며, 주근의 재생산량과 새롭게 발달된 측근의 수도 많았다. 하지만 측근의 길이 및 무게 생장은 작은 묘목이 더 많았다. 결론적으로 본 연구결과를 종합해 보면, 고품질의 묘목을 생산하기 위해서는 묘고가 큰 1-0묘를 생산하는 것이 다양한 장점을 가지며, 초기 묘고가 26 cm 이상의 큰 묘목은 15 cm로 단근하고, 초기 묘고가 24 cm 이하의 묘목은 10 cm로 단근하는 것이 가장 이상적인 단근길이라고 판단된다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1997년도 특별강연 및 춘계학술발표 개요집
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• pp.107-111
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• 1997

In this paper distribution of welding residual stress on the double fillet welded joint which exits and not exits root gap, i.e. full penetration and partial penetration is investigated by two dimensional cunduct and thermal elasto-plastic analysis. And stress distribution on notch-tip of the structure where welding residual stress regarded as initial stress and then external load is added is also investigated.

• Plant Biotechnology Reports
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• 제3권4호
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• pp.341-345
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• 2009

This study describes culture conditions for a plant regeneration system via a combined pathway of somatic embryogenesis and organogenesis in root explant cultures of the commercial rose cultivar 'Charming'. Root explants formed white calluses at a frequency of 30% after 6 weeks of culture on Schenk and Hildebrandt (SH) medium supplemented with $11mg\;1^{-1}$ 2,4-dichlorophenoxyacetic acid. After 6 weeks of transfer to SH medium without growth regulators, initial white calluses gave rise to globular somatic embryos at a frequency of 2.8%, which were subsequently dedifferentiated to embryonic tissues. Somatic embryos or embryonic tissues initially derived from root explants did not undergo development beyond cotyledonary stage. To produce adventitious shoots, embryonic tissues were sliced and cultured on SH medium with $0.5mg\;1^{-1}$ 6-benzyladenine. After 4 weeks of culture, 28% of embryonic tissue explants formed adventitious shoots. Regenerated shoots were rooted on half strength SH medium with $0.1mg\;1^{-1}$ ${\alpha}-naphthalaneacetic$ acid and subsequently grown to maturity. Root-derived embryonic tissues were proliferated by subculture, while retaining the capacity for shoot production for a few years.